I have a 1990 Cherokee it has the 4.0L, AW4 21 Spine Tranny, I have a tranny out of a 1994 Cherokee with the 4.0L AW4 23 Spline.

Right off the bat theres my problem, my old tranny is 21 spline, my new one is 23 spline, which would be easier, to take the main shaft out of the Transfer case and change it over to 23 spline, or take the shaft out of the tranny and make it 21 spline?

My transfer case is 21 Spline, NP231-J

 

IMO, if thats the route you wanna go I would swap shafts out of the tcase.

 

the transfer case is alot easier to work then the transmission.

 

Sorry to threadjack but what if he had the 23 spline transfer case. Would the transmission be a straight swap??? Any electronics involved or is the trans the same whether it's an h.o. or Renix?

 

My transfer case is 21 spline, the new transmission is 23 spline, and if Im not mistaken the Renix has the vacuum setup on the transfer case, and the H.O has electronic.